Preparation and Characterization of In Situ (TiC-TiB2)/Al-Cu-Mg-Si Composites with High Strength and Wear Resistance

Abstract

This study involved the preparation and characterization of in situ (TiC-TiB2)/Al-4.7Cu-0.32Mg-0.44Si composites with excellent mechanical and abrasive wear properties. The composites were synthesized in an Al-Ti-B4C system by combining combustion reaction synthesis with hot-pressed sintering and hot extrusion. The in situ TiB2 and TiC particles were of multi-scaled sizes ranging from 20 nm to 1.3 μm. The TiB2 and TiC particles effectively increased the yield strength (σ0.2), ultimate tensile strength (σUTS), hardness (HV), and abrasive wear resistance of the composites. The 40 wt.% (TiC-TiB2)/Al-4.7Cu-0.32Mg-0.44Si composite exhibited the highest σ0.2 (569 MPa), σUTS (704 MPa) and hardness (286 HV), which were 74%, 51% and 110% higher than those of the matrix alloy, respectively. Compared with the matrix alloy, the abrasive wear resistance of the 40 wt.% (TiC-TiB2)/Al-4.7Cu-0.32Mg-0.44Si composite was increased by 4.17 times under an applied load of 5 N and Al2O3 abrasive particle size of 13 µm. Micro-ploughing and micro-cutting were the main abrasive wear mechanisms for the Al-Cu-Mg-Si alloy and the composites.

Hot Workability of the Multi-Size SiC Particle-Reinforced 6013 Aluminum Matrix Composites

“…Aluminum matrix composites are widely used in aerospace and automotive industries because of their high specific strength, high specific stiffness, and high wear resistance [ 1 , 2 ]. For the reinforcing phase of aluminum matrix composites, ceramic particles, such as SiC, Al 2 O 3 , TiB 2 , are often chosen because of their high hardness and high thermal conductivity [ 3 , 4 , 5 ]. However, due to the addition of such ceramic particles, the strength and hardness of aluminum matrix composites increase, while the plasticity and toughness generally decrease.…”

“…Du et al [ 10 ] investigated the effect of the addition of RE and different sizes and amounts of SiCp on the activation energy, processing map, and strengthening mechanism and found that the size of the particles and the distance between the particles impacted the thermal stability of the composites. Gao et al [ 5 ] investigated (TiC-TiB 2 )/Al-Cu-Mg-Si composites and found that multi-scaled sizes of TiB 2 and TiC particles can effectively improve the tensile properties and wear resistance of the composites. Shen et al [ 15 ] studied bimodal-size SiCp-reinforced AZ31B magnesium matrix composites and found that the addition of bimodal-scale SiCp can significantly refine the grains of the substrate because micron-scale SiCp promotes recrystallization nucleation, while smaller nanoscale SiCp impedes grain boundary motion allowing grain refinement.…”